Supplement · Grade B

Bacopa Monnieri and medications.

Every documented pair, every citation. Below: 3 documented pairs grouped by mechanism.

Bacopa Monnieri is in the Distil supplement database, evidence Grade B. The page below lists every medication we have explicitly assessed it against.

Bacopa Monnieri is a traditional Ayurvedic herb studied mainly for memory consolidation, with supporting evidence for processing speed, anxiety reduction and neuroprotection. The evidence is Grade B, drawn from trials including Stough 2001 and the Kongkeaw 2014 meta-analysis, so the effect is real but modest. The most practical thing to know is patience: onset takes 8 to 12 weeks at minimum, and it is not fair to judge it before about week 10. Dosing is 300 to 450mg standardised to 55% bacosides. Early on, expect some gut upset and even a few weeks of fatigue or brain fog that usually clears by week four, and taking it with a fat-containing meal helps. The interactions to respect: Bacopa opposes anticholinergic drugs, and it may shift thyroid hormone levels, so anyone on thyroid medication should monitor. It pairs best with Lion's Mane for cognition. Set the slow timeline expectation up front so you do not abandon it too early.

Below are the 3 documented pairs we have explicitly assessed for Bacopa Monnieri: 3 amber. The pairs cluster around 2 mechanisms: Antithyroid drug interference and Additive thyroid-hormone effect. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.

Documented interactions

Antithyroid drug interference

Amber Carbimazole

Carbimazole works by lowering an overactive thyroid. Bacopa may gently raise thyroid hormone, so in theory it could pull in the opposite direction and make carbimazole a little less effective. This is based on animal studies rather than people, so it is a sensible caution rather than a firm warning. If you take carbimazole, mention bacopa to the clinician who manages your thyroid and keep to your usual thyroid blood tests so your dose can be reviewed if needed.

PMID 12065164 · BNF: Carbimazole

Reviewer-flagged: awaiting clinical-reviewer sign-off.

Amber Propylthiouracil

Propylthiouracil works by lowering an overactive thyroid. Bacopa may gently raise thyroid hormone, so in theory it could pull in the opposite direction and make propylthiouracil a little less effective. This is based on animal studies rather than people, so it is a sensible caution rather than a firm warning. If you take propylthiouracil, mention bacopa to the clinician who manages your thyroid and keep to your usual thyroid blood tests.

PMID 12065164 · BNF: Propylthiouracil

Reviewer-flagged: awaiting clinical-reviewer sign-off.

Additive thyroid-hormone effect

Amber Levothyroxine

Bacopa may gently raise your own thyroid hormone, so taken alongside levothyroxine it could in theory add to your total thyroid level and tip you towards having a little too much, with symptoms like a racing heart, feeling wired, or losing weight. This is based on animal studies rather than human ones, so it is a sensible caution rather than a firm warning. If you take both, mention it to the clinician who manages your thyroid and ask for a TSH blood test a few weeks later so your levothyroxine dose can be reviewed if needed.

PMID 12065164 · BNF: Levothyroxine

Reviewer-flagged: awaiting clinical-reviewer sign-off.

What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.

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For adults over 18. This tool gives evidence-graded information, not medical advice. Always discuss changes with your GP, especially if you take any medication, are pregnant, breastfeeding, or have a serious health condition.

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